I am having a similar experience with my GE/Jasco switches (45609s I think). I installed them 4 years ago and now the z-wave portion on them is starting to fail on at least four of them. The local control is still working fine.
Yes, air-gapped, power cycled, exclude/re-include. They just don’t have the build quality for the long term. I bought this particular one in '09 (date codes rock!).
On a side note, since I removed that dying GE dimmer, my Zwave mesh/response times has been super responsive. For future troubleshooting (ha!), worth doing a deep dive on individual devices that may not be communicating perfectly or is functioning in a quasi-configured state.
EDIT: I also happened to exclude my 2Gig alarm panel as a Secondary controller at the time I uninstalled the GE switch. (Never worked properly anyway.) So, I can’t be 100% certain that the failing switch was causing my intermittent Zwave problems, but it’s a pretty good bet based on observing the device’s behavior.